This research seeks a basis for more effective treatment of patients with malignant intracranial neoplasms through systemic examination of their experimental biology and selected clinical studies. The behavior of these neoplasms is being further defined by cellular and subcellular studies in cell cultures. Colony assay techniques have been developed to determine the effects of various chemotherapeutic agents and ionizing radiation on cell viability. Analysis of drug effect has included studies on cell kinetics, biochemical mechanisms and enzymatic properties. An animal brain tumor model has been developed and is being assessed. The clinical efficacy of various oncolytic drugs, particularly those in the nitrosourea group, has been evaluated in selected brain tumor cases. The methods available and results of treatment of recurrent medulloblastomas have been under review.